The Accidental Species: Misunderstandings of Human Evolution

The Accidental Species: Misunderstandings of Human Evolution

Henry Gee

Language: English

Pages: 224

ISBN: 0226284883

Format: PDF / Kindle (mobi) / ePub

The idea of a missing link between humanity and our animal ancestors predates evolution and popular science and actually has religious roots in the deist concept of the Great Chain of Being. Yet, the metaphor has lodged itself in the contemporary imagination, and new fossil discoveries are often hailed in headlines as revealing the elusive transitional step, the moment when we stopped being “animal” and started being “human.” In The Accidental Species, Henry Gee, longtime paleontology editor at Nature, takes aim at this misleading notion, arguing that it reflects a profound misunderstanding of how evolution works and, when applied to the evolution of our own species, supports mistaken ideas about our own place in the universe.

Gee presents a robust and stark challenge to our tendency to see ourselves as the acme of creation. Far from being a quirk of religious fundamentalism, human exceptionalism, Gee argues, is an error that also infects scientific thought. Touring the many features of human beings that have recurrently been used to distinguish us from the rest of the animal world, Gee shows that our evolutionary outcome is one possibility among many, one that owes more to chance than to an organized progression to supremacy. He starts with bipedality, which he shows could have arisen entirely by accident, as a by-product of sexual selection, moves on to technology, large brain size, intelligence, language, and, finally, sentience. He reveals each of these attributes to be alive and well throughout the animal world—they are not, indeed, unique to our species.

The Accidental Species combines Gee’s firsthand experience on the editorial side of many incredible paleontological findings with healthy skepticism and humor to create a book that aims to overturn popular thinking on human evolution—the key is not what’s missing, but how we’re linked.

wait for a LINE endonuclease to make a nick in the host DNA to allow LINE insertion—and slip in ahead of it. LINEs in the genome are accompanied by retinues of SINEs in the way dogs have fleas, and SINEs make up around 11 percent of the human genome. If LINEs have almost no genes, SINEs have none at all. All they have is a stretch of DNA (a sign of the SINE) that catches the attention of the host’s enzymes, which transcribe it into RNA; this RNA is then reversetranscribed by LINE reverse

the proverbial All Good Bookstores,8 in the original Old English and in Modern English translation, inures us against the revelation that there is only one known manuscript of the poem—and that narrowly avoided being destroyed in a fire in 1731. We are so used to the mass dissemination of information that it’s hard for us to imagine a time before the invention of printing, when books were fabulously rare and expensive custom-made products, copied from an original (or from other copies), with

of Old English poetry? Did poets of that vanished age regularly write about manly heroes and horrible monsters, or was this exceptional? Did they, perhaps, tend more toward kitchen-sink or sitcom? Did they always write in alliterative verse, or did they occasionally stray into rhyming couplets? Indeed, can we say anything reliable about the totality of the Old English literary tradition, given the few examples that now survive? That we should be practical and do what we can with the evidence we

no end of trouble, not least that the species itself was defined, in part, by a technology it was supposed to have created, when there was no certain way of linking tools and toolmakers. Ever since the 1960s, and with the discovery of more fossils of Homo habilis, people have worried about how to recognize fossils of Homo habilis should they find them,24 given that a defin- 134 CHAPTER EIGHT ing feature of the species is a kind of behavior that not only does not fossilize, but which might not

with too large a brain. Flo had to have evolved from something smaller still. Two possible solutions presented themselves. One was a study on island dwarfism in now-extinct hippopotamuses that lived on Madagascar, showing that in some cases, the brains of animals subject to island dwarfism would be reduced more than one would expect, even when one scaled a full-sized animal down to midget size.22 This makes sense in terms of energetics. A possible cause of island dwarfism is that castaways evolve